Spark plugs have been successfully used for decades in gasoline engines. Such a spark plug is described in DE 39 05 315 A1, in which a glass composition for a glass seal is described which forms an interference-suppression resistor and is temperature- and voltage-stable over a long period of time.
The glass seal as an ohmic interference-suppression resistor has produced good results over the decades and has met the requirements for electromagnetic compatibility (EMC) of motor vehicles. Increasing use of carbon fiber reinforced plastics in body construction, as a replacement for sheet metal parts, and the presence of more electronic devices in the vehicle can result in higher EMC requirements, which may not be fulfilled by the known spark plugs.